From the following risk factors the one that is beyond control is the biting of insects, as one can never have an idea of that. We can take ointments etc for avoiding it but still this is something beyond reach. These insect bites can cause fever, malaria, dengue, fatigue etc which sometimes also becomes the matter of life and death.
Usually, you are able to control your hygiene and nutrition. You can't control whether or not you live in poverty or get insect bites....I'm leaning toward B, although I could be wrong.
A nurse performing surgery without a surgeon present. Nurse aren't allowed to do surgery. All the other things on the list are actually what they're supposed to do. Hope this helps! ;)